src/libsystemd/sd-bus/bus-introspect.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2013 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include "bus-internal.h"
  23 #include "bus-protocol.h"
  24 #include "bus-signature.h"
  25 #include "string-util.h"
  26 #include "util.h"
  27 #include "bus-introspect.h"
  28
  29 int introspect_begin(struct introspect *i, bool trusted) {
  30         assert(i);
  31
  32         zero(*i);
  33         i->trusted = trusted;
  34
  35         i->f = open_memstream(&i->introspection, &i->size);
  36         if (!i->f)
  37                 return -ENOMEM;
  38
  39         fputs(BUS_INTROSPECT_DOCTYPE
  40               "<node>\n", i->f);
  41
  42         return 0;
  43 }
  44
  45 int introspect_write_default_interfaces(struct introspect *i, bool object_manager) {
  46         assert(i);
  47
  48         fputs(BUS_INTROSPECT_INTERFACE_PEER
  49               BUS_INTROSPECT_INTERFACE_INTROSPECTABLE
  50               BUS_INTROSPECT_INTERFACE_PROPERTIES, i->f);
  51
  52         if (object_manager)
  53                 fputs(BUS_INTROSPECT_INTERFACE_OBJECT_MANAGER, i->f);
  54
  55         return 0;
  56 }
  57
  58 int introspect_write_child_nodes(struct introspect *i, Set *s, const char *prefix) {
  59         char *node;
  60
  61         assert(i);
  62         assert(prefix);
  63
  64         while ((node = set_steal_first(s))) {
  65                 const char *e;
  66
  67                 e = object_path_startswith(node, prefix);
  68                 if (e && e[0])
  69                         fprintf(i->f, " <node name=\"%s\"/>\n", e);
  70
  71                 free(node);
  72         }
  73
  74         return 0;
  75 }
  76
  77 static void introspect_write_flags(struct introspect *i, int type, int flags) {
  78         if (flags & SD_BUS_VTABLE_DEPRECATED)
  79                 fputs("   <annotation name=\"org.freedesktop.DBus.Deprecated\" value=\"true\"/>\n", i->f);
  80
  81         if (type == _SD_BUS_VTABLE_METHOD && (flags & SD_BUS_VTABLE_METHOD_NO_REPLY))
  82                 fputs("   <annotation name=\"org.freedesktop.DBus.Method.NoReply\" value=\"true\"/>\n", i->f);
  83
  84         if (type == _SD_BUS_VTABLE_PROPERTY || type == _SD_BUS_VTABLE_WRITABLE_PROPERTY) {
  85                 if (flags & SD_BUS_VTABLE_PROPERTY_EXPLICIT)
  86                         fputs("   <annotation name=\"org.freedesktop.systemd1.Explicit\" value=\"true\"/>\n", i->f);
  87
  88                 if (flags & SD_BUS_VTABLE_PROPERTY_CONST)
  89                         fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"const\"/>\n", i->f);
  90                 else if (flags & SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION)
  91                         fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"invalidates\"/>\n", i->f);
  92                 else if (!(flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE))
  93                         fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"false\"/>\n", i->f);
  94         }
  95
  96         if (!i->trusted &&
  97             (type == _SD_BUS_VTABLE_METHOD || type == _SD_BUS_VTABLE_WRITABLE_PROPERTY) &&
  98             !(flags & SD_BUS_VTABLE_UNPRIVILEGED))
  99                 fputs("   <annotation name=\"org.freedesktop.systemd1.Privileged\" value=\"true\"/>\n", i->f);
 100 }
 101
 102 static int introspect_write_arguments(struct introspect *i, const char *signature, const char *direction) {
 103         int r;
 104
 105         for (;;) {
 106                 size_t l;
 107
 108                 if (!*signature)
 109                         return 0;
 110
 111                 r = signature_element_length(signature, &l);
 112                 if (r < 0)
 113                         return r;
 114
 115                 fprintf(i->f, "   <arg type=\"%.*s\"", (int) l, signature);
 116
 117                 if (direction)
 118                         fprintf(i->f, " direction=\"%s\"/>\n", direction);
 119                 else
 120                         fputs("/>\n", i->f);
 121
 122                 signature += l;
 123         }
 124 }
 125
 126 int introspect_write_interface(struct introspect *i, const sd_bus_vtable *v) {
 127         assert(i);
 128         assert(v);
 129
 130         for (; v->type != _SD_BUS_VTABLE_END; v++) {
 131
 132                 /* Ignore methods, signals and properties that are
 133                  * marked "hidden", but do show the interface
 134                  * itself */
 135
 136                 if (v->type != _SD_BUS_VTABLE_START && (v->flags & SD_BUS_VTABLE_HIDDEN))
 137                         continue;
 138
 139                 switch (v->type) {
 140
 141                 case _SD_BUS_VTABLE_START:
 142                         if (v->flags & SD_BUS_VTABLE_DEPRECATED)
 143                                 fputs("  <annotation name=\"org.freedesktop.DBus.Deprecated\" value=\"true\"/>\n", i->f);
 144                         break;
 145
 146                 case _SD_BUS_VTABLE_METHOD:
 147                         fprintf(i->f, "  <method name=\"%s\">\n", v->x.method.member);
 148                         introspect_write_arguments(i, strempty(v->x.method.signature), "in");
 149                         introspect_write_arguments(i, strempty(v->x.method.result), "out");
 150                         introspect_write_flags(i, v->type, v->flags);
 151                         fputs("  </method>\n", i->f);
 152                         break;
 153
 154                 case _SD_BUS_VTABLE_PROPERTY:
 155                 case _SD_BUS_VTABLE_WRITABLE_PROPERTY:
 156                         fprintf(i->f, "  <property name=\"%s\" type=\"%s\" access=\"%s\">\n",
 157                                 v->x.property.member,
 158                                 v->x.property.signature,
 159                                 v->type == _SD_BUS_VTABLE_WRITABLE_PROPERTY ? "readwrite" : "read");
 160                         introspect_write_flags(i, v->type, v->flags);
 161                         fputs("  </property>\n", i->f);
 162                         break;
 163
 164                 case _SD_BUS_VTABLE_SIGNAL:
 165                         fprintf(i->f, "  <signal name=\"%s\">\n", v->x.signal.member);
 166                         introspect_write_arguments(i, strempty(v->x.signal.signature), NULL);
 167                         introspect_write_flags(i, v->type, v->flags);
 168                         fputs("  </signal>\n", i->f);
 169                         break;
 170                 }
 171
 172         }
 173
 174         return 0;
 175 }
 176
 177 int introspect_finish(struct introspect *i, sd_bus *bus, sd_bus_message *m, sd_bus_message **reply) {
 178         sd_bus_message *q;
 179         int r;
 180
 181         assert(i);
 182         assert(m);
 183         assert(reply);
 184
 185         fputs("</node>\n", i->f);
 186
 187         r = fflush_and_check(i->f);
 188         if (r < 0)
 189                 return r;
 190
 191         r = sd_bus_message_new_method_return(m, &q);
 192         if (r < 0)
 193                 return r;
 194
 195         r = sd_bus_message_append(q, "s", i->introspection);
 196         if (r < 0) {
 197                 sd_bus_message_unref(q);
 198                 return r;
 199         }
 200
 201         *reply = q;
 202         return 0;
 203 }
 204
 205 void introspect_free(struct introspect *i) {
 206         assert(i);
 207
 208         safe_fclose(i->f);
 209
 210         free(i->introspection);
 211         zero(*i);
 212 }